f
\
UNITED STATES ENVIRONMENTAL PROTECTION A0ENCY
'WASHINGTON, D..C. 20460 1
.' ' i
, MAR,, 1, 1995 I
'OFFICE OF
SOLID WASTE AND EMERGENCY
RESPONSE
MEMORANDUM
SUBJECT:
FROM:
TO:
OSWER Directiye-x9610.
Making in UST/Correct
Elliott P.
Assistant Adiai
Regional Administrate
Regions I-X
Use of Risk|-Based Decision-
Action Programs
(/
I am pleased to provide the attached copy ;of OSWER Directive
9610.17, which encourages the use of risk-based; decision-making
in underground storage tank (UST) corrective action programs. A
risk-based approach is consistent with the Administrator's
efforts to ensure that our environmental cleanup programs are
based on the application of sound science and c-ommon sense and
are flexible and cost-effective. |
' , . " - ' _..' : t -
i ' .
EPA's regulations .for the UST corrective action program
already give States latitude to tailor their programs. They do
not specify cleanup levels or administrative procedures that
States must follow. They simply provide that State or local
cleanup programs must be protective of human heialth and the
environment. !
In other words, EPA's regulations allow States to make
choices about how they will design and conduct [their corrective
action programs. OSWER has long recognized and accepted the
.responsibility of helping States build corrective programs based
on these general principles. That was the impdtus for a
directive on corrective action .streamlining issiued two years ago
and is the impetus for the directive on risk-bajsed decision-
making. These directives are tools that Regional Offices can use
to help States build flexibility into their UST corrective action
programs. j
As presented in this policy statement, the use of risk-based
decision-making in UST corrective action programs is conceptually
and operationally compatible with the CERCLA remedial and RCRA
corrective action programs, EPA's guidance on development of
Recycled/Recyclable
f"rlnted wlth Soy/Canola Ink on paper that
contains at least 50% recycled fiber
-------
comprehensive State ground water protection programs, and the
environmental justice and brownfields initiatives.
OSWER's Office of Underground Storage Tanks (OUST) has been
working with Regional Offices and State and local UST programs
TT?LS£me ^lme to Promote the use of risk-based decision-making.
With the issuance of this directive, the Regional Offices now
have tangible evidence of EPA's support of this approach and
therefore should be able to promote it more effectively. In
addition, OUST will be working with the Regional Offices to help
them use risk-based decision-making in UST corrective action
activities on Indian lands.
The policy statement includes a description of our strategy
for^helping State and local UST programs implement risk-based
decision-making. In cooperation with a committee of the American
Society for Testing and Materials (ASTM), a group whose
membership includes both OUST and Regional Office staff is
planning a training program; a number of States have already
requested the training. "'''.'
i -,T5fmUSe °f risk-based decision-making could help state and
1°C31.UST. Programs deal with UST releases more quickly and
f^C1?ntly* Glven that 34'000 UST releases were reported in
1994 alone the need to speed up the corrective action process is
°?Vi°?!\ I1,h?pe * fan count on y°ur support of OSWER's ongoing
efforts to help State and local agencies streamline their
corrective action programs and introduce the use of risk-based
decision-making.
Attachment
cc:
UST/LUST Regional Program Directors
UST/LUST Regional Branch Chiefs
Regional Division Directors
ORC contacts
OSWER Office Directors
Assistant General Counsel, Superfurid Branch
OUST Management Team
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UnrtedSiites Environmental Protection Agency~j
Washington. DC 204«0 i
OSWER Directive Initiation Request
1. Directive Numb«r
9610.17
2. Originator Information
Name of Contact Person
Ivr Auerbach
May Coda
5401 (W)
Office
OUST
Telephone Code
703 308-8862
3. Title
Use of Risk-Based Decision-Making in UST Corrective Action
Programs
4. Summary of Directive (include brief statement of purpose)
The purpose of this directive is to encourage UST implementing
based decision-making in their corrective actionprograms and !"
on the application of this approach.
agencies to use risk-
to provide guidance
5. Keywords
Corrective action, risk, underground storage tanks, UST imple
meriting agencies
6a. Does This Directive Supersede Previous Directive(s)'r
b. Does It Supplement Previous Directive(s)?
X No
No
Yes What dn-ctive (number, title)
Yes What directive (number, title)
7. Draft Level
X A-SignedbyAA/DAA
B - Signed by Office Director
C - For Review S
Comment
D - In Development
8. Document to be distributed to States by Headquarters?
X Yes
No
This Request Meets OSWER Directives System Format Standards.
9. Signature of Lead Office Directives Coordinator
Shushona Clark, OUST Directives Cbordinator
Date
10. Name and Title of Approving Official
Lisa Lund, Acting Director, OUST
Date
EPA Form 1315-17 (Rev. 5-87) Previous editions are obsolete.
OSWER OSWER
'E DIRECTIVE DIRECTIVE
OSWER
DIRECTIVE
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xvEPA
United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
DfRECTIVE NUMBER: 9510.17
TITLE: Use of Risk_Based Decision-Making in UST Corrective
Action Programs
APPROVAL DATE:
EFFECTIVE DATE:
ORIGINATING OFFICE: Office of Underground Storage
Tanks
SPINAL
D DRAFT
STATUS:
REFERENCE (other documents):
OSWER OSWER OSWER
TE DIRECTIVE DIRECTIVE Dl
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OSWER Directive 9610.17
March 1, 1995
USE OF RISK-BASED DECISIOl^^KING
IN UST CORRECTIVE ACTION PROGRAMS
INTRODUCTION AND STATEMENTOFPURPOSE i
."''- '. '.. ' '.' "'-.'. j1
As applied to corrective action at UST release sites, risk-based decisiori-making is a
process that utilizes risk and exposure assessment methodology to help UST implementing
agencies make determinations about the extent and urgency of corrective action and about the
scope and intensity of their oversight of corrective action by UST owners and operators.
The primary purpose of this policy statement is to encourage ihe use of risk-based
decision-making as an integral part of the corrective action process at: sites where leaking
underground storage tank (UST) systems have released petroleum prcklucts into the
environment and thus created risks to human health and the environment. In addition, this
policy statement provides guidelines to help UST implementing agencies develop and use
risk-based decision-making in a manner consistent with the Federal law and regulations
applicable to UST corrective action. :Some State arid local'UST implementing agencies have
already taken steps to initiate the use of risk-based decision-making in .their corrective action
programs. EPA plans to begin using risk-based decision-making where it implements such
programsprimarily on Indian lands^-and expects to work with State jand local agencies to
help more of them initiate or improve risk-based processes. j
' ' ' ,!'_,, , '
Where risk-based decision-making is incorporated into the US^T corrective action
process, the result is usually called risk-based corrective action (RBOA). The American
Society for Testing and Materials (ASTM) recently issued an emergency standard for risk-
based corrective action; the ASTM standard provides a detailed scientific and technical
framework that can be adapted by UST implementing agencies for use in their corrective
action programs. Thus, the ASTM standard constitutes one possible jstarting point for \
development of a process using the risk-based approaches described in this policy statement.
Additional information about the ASTM standard appears later in this document.
Risk-based decision-making is consistent with EPA policies arid regulations governing
UST corrective action and with the approaches being taken by other EPA programs involved
in protection of ground water and cleanup of environmental contamination. ,
' - . ' ,' - ; '.;.. ' ' .] . . ;"'.- .. '.
EPA's regulations dealing with UST corrective action [40 pFR Part 280] are
aimed at protecting human health and the environment. Under the regulations, UST
implementing agencies, including EPA, are expected to establish goals for cleanup of UST
releases based on consideration of factors that could influence humani and environmental
exposure to contamination. Where UST releases affect ground water being used as public or
private drinking water sources, EPA generally recommends that cleanup goals be based on
health-based drinking water standards; even in such cases, however, [risk-based decision-
making can be employed to focus corrective action and guide UST implementing agencies'
oversight activities. ,-.:' 'j -'..'
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OSWER Directive 9610.17
March 1, 1995
, EPA's guidance on the development of Comprehensive State Ground Water
Protection Programs (issued November 1992) urges States to take current and prospective
uses of ground water, as well as relative risks to human health and the environment, into
consideration when establishing goals for the remediation of contaminated ground water.
Within this framework, EPA recommended that States use health-based drinking water
standards as the remediation goal for ground water that is already used, or could reasonably
be expected to be used, for drinking water. In all other cases, States can set cleanup goals
based on aquifer priority and other site-specific considerations.
» In the Superfund program, risk-based decision-making plays an integral role in
determining whether a hazardous waste site belongs on the National Priorities List. Once a
site is listed, qualitative and quantitative risk assessments are used as the basis for
establishing the need for action and determining remedial alternatives. To simplify and
accelerate baseline risk assessments at Superfund sites, EPA has developed generic soil
screening guidance that can be used to help distinguish between contamination levels that
generally present no health concerns and those that generally require further evaluation.
The Resource Conservation and Recovery Act (RCRA) Corrective Action program
also uses risk-based decision-making to set priorities for cleanup so that high-risk sites ,
receive attention as-quickly as possible; to assist in the determination of cleanup standards;
and to prescribe management requirements for remediation of wastes.
BACKGROUND
^ In the 1980s, to satisfy the need to start corrective action programs quickly, many
UST implementing agencies decided to utilize regulatory cleanup standards developed for
other purposes and apply them uniformly to UST release sites to establish cleanup
requirements. With experience, however,, it has become increasingly apparent that applying
such standards without consideration of the extent of actual or potential human and
environmental exposure is an inefficient means of providing adequate protection against the
risks associated with UST releases. Similarly, UST implementing agencies have found that
applying identical reporting and review procedures to the planning and conduct of all
corrective actions is inefficient for them and for UST owners and operators. These problems
have become increasingly serious as the number of UST release sites has multiplied.
As of October 31, 1994, more than 270,000 releases had been reported nationwide.
Li 1994, 34,000 confirmed releases were newly reported. The upcoming 1998 deadline for
upgrading, replacing, or closing UST systems likely will increase that number; as owners
and operators look at their tank systems to decide whether to upgrade, replace, or close
them, they often will discover contamination not previously identified.
Though the number of releases is, and will continue to be, daunting, regulators have
made tremendous progress over the last six years. All States and territories, as well as a
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OSWER Directive 9610.17
March 1, 1995
', *
!
number of local governments, have corrective action programs employing a total of about
1,500 technical staff. Nearly all corrective actions are undertaken by JUST owners and
operators with State and local oversight. Cleanups have been initiate^ at more than 209,000
sites (of the more than 270,000 at which releases have been reported); arid completed at more
than 107,000 of them. In spite of this progress, UST implementing agencies face the
challenges posed by the more than 163,000 cleanups still underway.
Forty-six States have established State financial assurance fundfs to help owners and
operators satisfy the Federal statutory requirement for evidence of ability to pay the costs of
corrective action. These funds serve as both a mechanism for satisfying the Federal financial
responsibility requirements and a source of financial assistance to help UST owners pay for
corrective actions. While these funds together collect more than $1 billion dollars a year,
many are beginning to face solvency issues as reimbursement requests increase. Currently,
claims waiting to be paid exceed $1;3 billion. Unfortunately, when reimbursement is not
immediately available, corrective actions tend to slow down.
!
To help UST implementing agencies deal with these challenges, EPA provides support
for streamlining (i.e., simplifying and accelerating) administrative and field investigation
processes; promotes the use of cleanup technologies that offer alternatives to traditional
excavation and landfilling (for soils) and pump-and-treat (for groundv/ater); and assists
States in building strong State assurance funds. EPA believes that risik-based corrective
action processes are another tool that can facilitate UST implementing agencies' efforts to
move all sites forward expeditiously while still assuring protection of i human health and the
environment. Taking risk into account is not a new idea. In November 1992, in its
guidance on streamlining of corrective action processes (OSWER Directive No. 9650.13:
Streamlined Implementation of UST Corrective Action Requirements)^ EPA described four
situations in which risk factors could be taken into account in corrective action decision-
making. This policy statement builds on concepts articulated in that (document.
WHAT IS RISK-BASED DECISION-MAKING?
Risk-based decision-making is a process UST implementing agencies can use to make
determinations about the extent and urgency of corrective action and about the scope and
intensity of their oversight of corrective action by UST owners and operators.
, ' i - - . '' , .
The real value of risk-based decision-making lies in its potential to help UST
implementing agencies and UST owners and operators oversee/manage cleanups of UST
releases based on relative risks to human health and the environment! In addition, risk-based
decision-making can provide a coherent decision-making framework l;o help keep transaction
costs under control. Thus, while risk-based decision-making can be as protective of human
health and the environment as other approaches, it offers a scientificjjlly sound and
administratively effective way to respond to the pressures for timely iaction at large numbers
of sites and efficient use of both public and private resources. It is important to recognize
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OSWER Directive 9610.17
March 1, 1995
that risk-based decision-making is not intended to be primarily a money-saving tool, even
though its use may save money in many cases. At high-risk sites (which account for only 20
to 30 percent of all sites), risk-based cleanups could cost more than those based on other
procedures for establishing cleanup goals.
Risk-based decision-making is a mechanism for identifying necessary and appropriate
action throughout the corrective action process. Depending on known or anticipated risks to
human health and the environment, appropriate action may include site closure, monitoring
and data collection, active or passive remediation, containment, or institutional controls. Li
aU cases, the objective is the same, i.e., to ensure that adequate protection of human health
and the environment is provided. The availability of options such as allowing contamination
to remain in place or using institutional controls to prevent exposure will depend on '
applicable State and local laws and regulations. '
WHAT RISK-BASED DECISION-MAKING IS NOT
There are a number of common misconceptions about risk-based decision-making.
This section attempts to deal with several of them.
» Risk-based decision-making is not just a means of identifying sites requiring no
further action. Once an UST release is confirmed, the key decision to be made at all stages
of the corrective action process is what action is required in order to protect human health
and environmental quality. Only when it can be determined that all necessary risk-reduction
action has been completed or alternative measures have been taken can a site be closed out.
Risk-based decision-making is not just a means of identifying sites at which
corrective action can be deferred. EPA encourages UST implementing agencies to
categorize sites for the purposes of identifying appropriate initial responses and providing
guidance to UST owners and operators on steps that will lead to timely completion of
cleanup. EPA does not support the use of risk-based decision-making to prioritize sites, if
prioritization implies that some sites would receive attention/action while others are ignored.
EPA encourages UST implementing agencies to ensure that UST owners and operators take
action as promptly as possible at all UST release sites and to concentrate their own resources
on conducting oversight of corrective actions at sites posing the highest risks. Prompt action
at low-nsk sites may include determinations that monitoring or interim actions are necessary
or that no active cleanup is necessary; a risk-based decision-making process can help make
such determinations defensible.
Risk-based decision-making does not supplant the initial steps specifically
required by EPA regulations to define site characteristics, contaminant levels, and actual or
potential exposures; indeed, in a risk-based process, these steps are critical. Likewise, action
to mitigate immediate threats to human health or the environment is required, and a risk-
based process can help UST implementing agencies make timely determinations of the need
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F
^V OSWER Directive 9610.17
. March 1, 1995
. ' '- ^ , .[ - - - --
for such action. In addition, when establishing monitoring and reporting requirements,
remediation goals, and identifying alternatives to active remediation, a risk-based process can
provide more flexibility than traditional one-standard-for-all-sites approaches.
I ' . ..-..- . . ' i. -..-'
I Risk-based decision-making does not require multiple studies of site
characteristics, cleanup options, or other factors at all sites. In all cases, data collection
and analysis need not be more elaborate or extensive man is necessary to provide
scientifically and technically sound answers to the questions at handto perform an initial site
assessment; to provide data needed for exposure assessment; to provide a basis for
establishing cleanup goals. For example, expedited site assessment involving the use of field
measurements and geophysical techniques is consistent with risk-based decision-making, as
long as it provides the data that UST implementing agencies have determined are necessary
to categorize sites or take other steps in the process. j
- i "
''..' '
RELATIONSHIP TO ASTM STANDARD ON RISK-BASED COIRRECITVE ACTION
This policy statement lays out broad guidelines for the use of :jisk-based decision-
making in UST corrective action programs. A detailed framework fcjr taking risk factors
into account in making corrective action decisions has been developed by ASTM and issued
as an emergency standard entitled Guide for Risk-Based Corrective Action Applied at
Petroleum Release Sites [ES-38-94]. The ASTM standard is an example of how risk-based
decision-making can be incorporated into the UST corrective action pjrocess in a manner
consistent with this policy statement EPA supported and participated in developing
ES-38-94 and believes that its technical content is sound. j
. . - i- -
UST implementing,agencies need not use ES-38-94 in its entirety, but it may be a
good starting point for the development of a risk-based process tailonsd to applicable State
and local laws and regulatory practices. One limitation that UST implementing agencies
must take into account when using ES-38-94 is that it deals exclusively with human health
risks; there will, of course, be cases in which ecological risks have to be considered in
establishing cleanup goals. !
; ' I ' ' ' ,' '
With support from EPA and other organizations, the ASTM Subcommittee E50.01 on
Storage Tanks, which developed ES-38-94, is also developing tools ajnd a training program to
help UST implementing agencies understand the concepts of risk-bas<;d decision-making and
the ASTM standard. Tools being developed include a set of step-by-|step worksheets,
generic training materials, and an ASTM program to certify instructors who are qualified to
provide training. EPA is committed to ensuring that quality training fis available to UST
implementing agencies interested iri considering the adoption of a risk-based approach.
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> , OSWER Directive 0610.17
March 1, 1995
WHERE AND HOW IN THE CORRECTIVE ACTION PROCESS
CAN RISK-BASED DECISION-MAKING BE USED?
Wherever there is a confirmed UST release, owners and operators must take action to
prevent further releases, control emergency conditions (e.g., fire and explosion hazards),
remove free product, if any, and perform a site assessment. UST implementing agencies
should ensure that field measurements and/or laboratory analysis to determine the extent of
contamination are appropriately used. Timely collection of appropriate data during the site
assessment is critical to successful utilization of risk-based decision-making. After the site
assessment is completed, risk-based decision-making comes into play. The principal-but not
necessarily the only-uses of risk-based decision-making are described here.
To categorize or classify sites: Comparison of contaminant levels at UST release
sites with risk-based criteria can be used to place sites into categories for which there are
prescribed initial response actions and/or subsequent steps in the corrective action process.
For each category, UST implementing agencies could direct owners and operators to proceed
with cleanup according to an acceptable standardized approach. Thus, at low-risk sites, UST
owners and operators often would not have to develop site-specific corrective action plans
and often could take the prescribed steps without constant oversight by UST implementing
agencies. At high-risk sites, UST implementing agencies' policies regarding submittal of
corrective action plans and oversight of UST owners' and operators' activities can be
incorporated into the steps specified for that category. Such a process could make it possible
for appropriate action to be taken in timely fashion at all sites. EPA is not prescribing or
recommending any particular categorization scheme. UST implementing agencies choosing
to take this approach will need to develop their own. The one included in the ASTM
standard is a potential starting point. . , .
To aid in establishing cleanup goals: Risk-based cleanup goals can be either
generic or site-specific. Generic goals based on conservative assumptions about factors that
may influence human and environmental exposures can be developed for contaminants
generally present at UST release sites. Such generic cleanup goals can be designed to
provide adequate protection of human health and the environment in the great majority of
corrective action cases. Their use generally will cut down on site-specific data collection and
analysis and thus expedite corrective action. There are sites where it will be more cost-
effective to gather site-specific data and set site-specific cleanup goals based on exposure and
risk assessment methodology. Where conditions are similar to those used to establish the
applicable generic cleanup goals, site-specific goals may not be significantly different, and
the costs of the additional data collection and analysis may negate any savings associated with
site-specific goals. UST implementing agencies also should consider the administrative costs
of negotiating and overseeing the implementation of site-specific goals as they design and
develop a risk-based process. EPA believes that a balance can be achieved between the costs
and benefits of employing such a process.
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OSWER Directive 9610.17
March 1, I,
EPA believes that UST implementing agencies should have flexibility to implement,
or experiment with, risk-based decision-making in various ways reflecting their differing
regulatory mandates. Risk-based decision-making can be phased-in tip allow time for needed
statutory or regulatory changes. Also, it can be implemented initially through pilot projects
to test or demonstrate its effectiveness. , !
i '
EPA is willing to provide advice and assistance, as explained later in this policy
statement, but decisions on whether and how to proceed are solely within the province of
UST implementing agencies. In all cases, of course, the process must provide adequate
protection of human health and the environment. This section provides general advice on
ways to prepare for risk-based decision-making implementation. j
» Building internal and external support: UST regulators,] tank owners and
operators, consultants, lending institutions, and environmental and community interest groups
all may have concerns about the use of risk-based decision-making in corrective action
programs. For example, where a risk-based process might lead to ajdecision to leave some
contamination in place, mere may be concerns about liability for the [consequences of
possible future exposure to such contamination. To enlist the support of interested groups,
UST implementing agencies should explain their reasons for wanting! to move toward risk-
based decision-making and address concerns that such groups may hsiive. Involving such
groups in deciding whether and how to use risk-based decision-making will be very valuable
in ensuring the long-term success of this approach. ' \
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Up-front decisions: Decisions will need to be made about a range of scientific and
technical, regulatory, and organizational issues.. For example, UST implementing agencies
will have to define the criteria (or screening levels) and data requirements for categorizing or
classifying sites; decide which risk assessment, fate and transport, arid exposure models can
, be used in performing analyses; delineate procedures to be used in deciding upon cleanup
requirements; and identify the circumstances, if any, under which IJST owners and operators
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OSWER Directive 9610.17
March 1, 1995
will be allowed to use institutional controls or alternative compliance points. UST
implementing agencies will also have to make decisions on program management issues, such
as where and when oversight and review will occur and how intensive they will be.
Coordination with State funds may be a critical issue.
Simulations: After designing a risk-based decision-making process, UST
implementing agencies may find it beneficial to run several representative sites through the
process. Such simulations-preferably using sites that have already gone through corrective
action-may help UST implementing agencies identify problems that were not foreseen when
the process was being designed and anticipate questions that UST owners and operators
consultants, and contractors may ask. . ''
Training: Before implementing a risk-based decision-making process, and
periodically thereafter, UST implementing agencies will have to train their own staff
members, as well as consultants and contractors frequently involved in corrective action to
ensure that they thoroughly understand the risk-based decision-making process and how it
affects their work. Basic training in risk "and exposure assessment and in the use of fate and
transport models, and in other scientific and technical areas may also be necessary* Such
training, as well as participation in dry-runs of the risk-based decision-making process will
be extremely useful not only for UST regulatory staff, but also for consultants, contractors
lenders, and other stakeholders. Tank owners and operators may not need in-depth training
but an overview of the risk-based decision-making process may be beneficial; among other '
things, it may help them oversee and interact with the consultants and contractors they hire to
undertake corrective action at their facilities.
/
Evaluation: With implementation of risk-based decision-making, as with all
improvement efforts, it is important to be able to document and assess results. For this
purpose, UST implementing agencies should identify up-front the ways in which they will
measure the impacts of risk-based decision-making and ensure that appropriate data are
collected. Developing such measures in advance and collecting real-time data usually will
make evaluations less costly and more useful than they otherwise would be and may enable
UST implementing agencies to identify opportunities for continuing improvements.
ENVIRONMENTAL JUSTICE CONSIDERATIONS
Residents of low-income and minority neighborhoods may have disproportionately
high health nsks from environmental pollution-often because many manufacturing and
processing, waste treatment and disposal/and other commercial and industrial facilities are
located in and around such neighborhoods. EPA urges UST implementing agencies to ensure
ffiat the cumulative health risks to people living in such areas are taken into consideration in
determining the extent and urgency of needed cleanups of releases from UST systems A
nsk-based approach should allow for consideration of these factors at appropriate points in
the corrective action process.
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OSWER Directive 9610.17
March 1, I!p95
' f :.
REDEVELOPMENT OF CONTAMINATED SITES j
' [-
Many former commercial arid industrial sites containing old or abandoned USTs are
being shunned by industries and developers. Their reluctance to use |such sites is due in part
to uncertainty about their potential liability for cleanup of contariiinatiion and the perceived
imbalance between the value of such properties and potential cleanup j costs. Such sites often
are called brownfields-reflecting the appearance of vacant lots where; lack of interest in
cleaning up or reusing contaminated land has contributed to the geneiral deterioration of urban
areas. ''.'. ' ',"...'[' ' ' '
Within EPA's Office of Solid Waste and Emergency Response (OSWER), a strategy
is being developed that will include actions dealing with UST-relatedjbrownfield sites. This
strategy will outline measures to prevent sites where UST facilities aire located from
becoming brownfields and to facilitate assessment, cleanup, and reuse of sites already
contaminated by UST releases. Prevention measures will include efforts to encourage
compliance with the upgrading, replacement, or closure requirements^ that take effect in
December 1998 and promulgation of a regulation dealing with lender] liability for cleanup of
contaminated sites. > ,
UST implementing agencies can expedite assessment and cleaitiup of UST release sites
through streamlining of corrective action processes, development of strong State assurance
funds, and use of risk-based decision-making. By using a risk-based; process that provides
for categorization of UST release sites, allows consideration of site-specific factors, where
appropriate, and focuses attention on the highest risk siteSj States cant deal with brownfields
sites in a timely fashion and thus encourage economic redevelopment!. EPA will work with
other UST implementing agencies to carry out this strategy. j
EXAMPLES OF STATES' USE OF RISK-BASED DEOSION-MtAKING PROCESSES
N . I '"'''
Attached to this policy statement is a description of several .examples of risk-based
processes already being used by State and local governments. Whilej those described here
were developed independent of the ASTM standard, they are similarito it in many respects.
Some companies in the private sector also have developed such processes for their own use.
HOW EPA CAN HELP UST IMPLEMENTING AGENCKS [
*" . ' " ' ' ! '.
EPA'S Office of Underground Storage Tanks (OUST) and Regional Offices (ROs)
will play an active role in promoting the development and implementation of risk-based
decision-making processes through information sharing and technical! assistance. EPA
expects to offer support by funding peer matches through the Association of State and
Territorial Solid Waste Management Officials (ASTSWMO); coordinating training programs
with ASTM and the American Petroleum Institute (API); preparing zlnd circulating write-ups
of State and local experiences with risk-based decision-making; providing forums for
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OSWER Directive 9610.17
March 1, 1995
discussions of risk-based decision-making at our national conferences; and providing targeted
assistance similar to that being provided for corrective action streamlining. Regional Offices
will play a role in this effort by negotiating State Improvement Projects; coordinating and
participating in training programs and targeted assistance projects. State and local UST
managers should contact EPA Regional Office UST program staff for answers to specific
questions about risk-based decision-making or to determine who to contact for the answers.
( -
In implementing the UST program on Indian Lands, the Regional Offices will move
toward incorporating risk-based decision-making into their corrective action processes.
Doing so will enable the Regional Offices to use their resources more efficiently and gain
experience that will improve their ability to help other UST implementing agencies design
and implement risk-based decision-making processes.
CONCLUSION
Cleaning up contamination from leaking UST systems poses tremendous
administrative, financial, and technical challenges for UST regulators. To cope with these
challenges and succeed in protecting human health and the environment, UST implementing
agencies, including EPA, will have to employ a broad range of traditional and innovative
approaches. This policy statement builds on our experience with corrective action at leaking
UST sites and continues EPA's support of innovative approaches by encouraging regulators
to adopt risk-based decision-making as an integral part of the corrective action process. EPA
believes that risk-based decision-making will enable UST implementing agencies to simplify
and expedite their corrective action programs.
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OSWER Directive 9610.17
March 1, 1995.
ATTACHMENT A
EXAMPLES OF STATES' USE OF RISK-BASED DECISION-MAKING
IN UST CORRECTIVE ACTION PROGRAMS
Texas', . , ' [''..
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Texas recently modified its corrective action program; its now risk-based in its
approach to prioritizing and remediating leaking UST tank sites. la Texas, risk-based - - ' _
.corrective action refers to a case-by-case consideration of the actual or reasonable potential
for public and environmental exposure to contaminants in the determination of the timing,
type, and degree of site remediation. To implement the new risk-based corrective action
program, the Texas Natural Resource Conservation Commission created a new site
classification system and site assessment protocol, and adopted new procedures for
developing risk-based cleanup levels. In addition, the Commission contracted for the «
development of a guidance document on fate and transport modeling tip support its review of
risk assessments reports. 'I
Texas began the transition to a risk-based program by developing a new site
classification system. Site classification is based upon site similarity to specific exposure
scenarios. Sites fall into one of four classes. Class 1 sites represent :an actual or probable
impact to public health and safety and may require emergency abatement action or interim
containment measures. Class 4 sites pose no threat to the public or ttie environment. Class
2 and 3 sites pose intermediate threats to public health and safety and) the environment.
Site classification is determined by using the new Limited Site i Assessment (LSA)
protocol. The purpose of the LSA is not to define the full lateral and, vertical extent of the
contaminant-affected area but to evaluate the degree of contamination I at the site, identify the
media affected, determine critical hydrogeologic properties, and identify receptors potentially
affected by the release. Decisions on the urgency of subsequent corixjctive actions are based
on site classification. i
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Site cleanup levels are determined by the responsible party using one of two
established procedures. Plan A is a conservative approach based on established default
exposure assumptions and risk management considerations. Plan A generally requires less
rigorous assessment and regulatory review; UST owners and operators therefore may be able
to start site cleanup quicker. Plan B is a site-specific risk assessment! procedure which
incorporates less default conservatism and allows for more site-specific considerations. Plan
B typically involves more rigorous assessment and regulatory review jthan Plan A, but it may
result in a more focused cleanup effort. However, proceeding under jPlan B may require
institutional controls (e.g., land use restrictions, deed certifications) tip ensure that exposure
conditions do not change. Plan A and Plan B are analogous to Tier I and Tier H in ASTM
ES-38.
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OSWER Directive 9610.17
March 1, 1995
Ohio
,OBO x developed corrective action rules that include a Site Feature Scoring System
(SPSS) and risk-based action levels to assess corrective action sites. Ohio developed a risk-
based approach which uses four tiers of risk assessment. The complexity of risk assessment
increases from Tier I through Tier IV. The process initially uses conservative scenarios and
assumptions; less conservative assumptions are introduced as additional1 site-specific data are
provided to justify them.
Based on data collected during an initial site check or assessment, the responsible
party completes an SPSS form, which determines whether or not additional corrective actions
are necessary. If contamination is present at or below the action level, further remediation is
not required at that time. If the action levels are exceeded, additional corrective actions are
necessary.
As an alternative to Tier I (the SPSS action levels), Ohio also allows owners and
operators to conduct risk assessments to determine whether clean-ups are necessary and to
develop site-specific target cleanup levels. Tier H, a baseline risk assessment, uses
conservative assumptions about pathways and chemicals. Tier m is a more detailed risk
assessment and, if sufficient data exist, specific pathways (e.g., groundwater ingestion) may
be eliminated in this tier. Tier IV consists of a risk assessment with Monte Carlo Sensitivity
Analysis. This tier requires additional site-specific information to justify less conservative
assumptions about pathways .and chemicals.
Illinois
On September 13, 1993, Illinois enacted new legislation governing UST corrective
actions. The goals of the legislation are to protect human health and the environment at the
lowest possible cost, lower cleanup cost and reduce delays in reimbursement, provide for
timely review and response, arid eliminate delay in remediation due to lack of funds
Illinois' revised program incorporates risk in the site prioritization and review processes and
in the development of site-specific cleanup levels.
Site classification follows early corrective action activities; data obtained as part of
early action can be used to classify sites. Sites are classified as high priority, low priority
or no further action based on five "triggering" criteria: 1. physical soil classification- 2
setback zone distance; 3. migratory pathways; 4. Class HI groundwater distance; and 5
surface water impact. If a site passes on all five criteria, it is classified a no further action
site. If a site fails on criteria #2 through #5, it is classified a high priority site. If a site
fails on criteria #1, it can be classified as either a high or low priority site depending on the
results of groundwater monitoring.
A licensed professional engineer must evaluate all five criteria. UST owners and
operators can bypass site classification by performing complete cleanup during the early
action phase; however, cleanup costs beyond the early action minimum are not reimbursable
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OSWER Directive 9610.17
March 1, 1995
r
unless approved by the Illinois EPA. Based on an early sampling of site classification
approvals, the Illinois EPA expects that 15-20 percent of reported incidents will be high
priority sites, 65-70 percent will be no further action sites, and the remainder will be low
priority sites. [ ,
I. . ' : .. ,/,." .' ' ' I ' ' ' '- '- .' "'
I Regulations implementing the new legislation were effective September 23, 1994.
[ These new regulations include remediation objectives for groundwateri and soil.
Groundwater objectives apply to potable resource groundwater and are;-equal to Federal
Maximum Contaminant Levels (MCLs). Soil cleanup objectives are biased on a three-tier
system with the goal of protecting groundwater. Tier I includes a Lobk-up Table that
contains baseline numericalcleanup levels for six indicator contaminants. Tier n cleanup
levels are determined based on equations using site-specific parameters. Tier m cleanup
levels are based on performance of risk assessments using formal methodologies (like the
ASTM methodology set forth in ES-38) or common sense methods for situations where there
are physical limitations (such as permanent buildings and/or highways).
Hawaii j
Hawaii offers owners and operators three options for cleaning up contaminated soil
, and groundwater to levels that are protective of human health and the environment Option 1
allows owners and operators to clean up soil and groundwater to levels established by the
Department of Health. Option 2 allows owners and operators to propjose alternative cleanup
levels based on risk assessment. Option 3 allows owners and operators to select exposure
prevention management to eliminate existing exposure pathways. j
. ' " .-..' ' ' - ' ';." ' f ' .
Of the three available cleanup options, Option 1 is the simplest and most direct. The
' Department of Health has established cleanup levels for soil and grouitidwater with protection
of human health and the environment as the ultimate goal; The Department has attempted to
establish protective levels that can be practically achieved by owners iind operators at many
UST release sites. In cases where these criteria are impractical, the lisk assessment option
and the exposure management option are available to owners and operators.
Where owners and operators propose to leave contamination in soil and water above
the recommended.cleamip criteria and where complete exposure pathways do exist, the levels
of the contaminants left in-place must be supported by a site-specific, j quantitative risk
assessment. The risk assessment must conclusively, demonstrate that |the levels of
contaminant left in place do not pose a threat to human health and thei environment. Because
the preparation of a risk assessment involves numerous complex and time-consuming tasks,
the Department recommends that owners and operators not enter into:this process without
fully considering all alternatives, including application of alternative types of technology to
meet the recommended cleanup standards. j
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The Department offers owners and operators a third option, exposure prevention
management, which relies on recognition of the lack of exposure pathways inherent to a site,
or alternatively, recognizes and relies upon the construction of man-n^ade barriers (such as
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OSWER Directive 9610.17
March 1, 1995 ,
asphalt or concrete pavements) to effectively eliminate existing exposure pathways. This
option is viewed as a temporary (non-permanent) cleanup option since the potential does exist
for the evolution of exposure pathways in the future and because barriers to exposure
pathways are not permanent.
i '', X
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Massachusetts l
Massachusetts redesigned its Waste Site Cleanup Program to streamline and accelerate
cleanup of releases of oil and hazardous material to the envirbnment. The previous program
relied heavily on direct oversight of privately-funded assessment and cleanup actions. The
redesigned program allows the private sector to take more responsibility for timely site
assessment and cleanup and allows the Department of Environmental Protection to focus its
resources on responding to emergency spills and on finding the worst hazardous waste sites
and getting them cleaned up.
A cornerstone of the new program is reliance on Licensed Site Professionals (LSPs),
experts in assessment and cleanup, who are licensed by an independent state regulatory '
board. LSPs are employed by UST owners and operators to oversee site assessment and
remediation and to ensure that such actions are performed in compliance with the
Massachusetts Contingency Plan (MCP). By hiring an LSP, UST owners and operators pan
proceed at most sites on their own and at their own pace. '
In the redesigned program, the Department receives notification of releases and
threats of releases that exceed specific .thresholds. Releases that have not been cleaned up
within one year of notification must be scored using the Numerical Ranking System (MRS).
The JNRS ranks sites using specific criteria and a scoring system based on the existing and
potential risks posed by the site to public health, natural resources, and environmental
receptors. Generally, sites that score below 350 are Tier H sites. Assessment and cleanup
actions can proceed at these sites under the oversight of an LSP and without a Waste Site
Cleanup permit or approval. Sites that score 350 or above, as well as sites that are located
within certain groundwater resource areas, are Tier I disposal sites. These sites require a
permit to proceed with further response actions.
Response actions are complete when a condition of "no significant risk" of harm to
health, safety, public welfare, or the environment exists or has been achieved. This standard
requires consideration of both current and reasonably foreseeable uses of a site and its
surrounding area. The MCP provides three options for defining alevel of "no significant
risk" or "how clean is clean enough." Method 1 uses clear numeric standards for more than
100 common chemicals in soil and groundwater. Method 2 allow for some adjustments in
these standards to reflect site-specific conditions. Method 3 allows cleanup requirement
goals to be defined on the basis of a site-specific risk assessment. With some limits, UST
owners and operators can choose among these methods.
At the conclusion of response activities, a Response Action Outcome Statement must
be filed with the Department to document the achievement of a permanent or temporary
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OSWER Directive 9610.17
March 1, 1SJ95
solution. Where it is not feasible to achieve a permanent solution, the MCP recognizes
where a temporary solution-a major milestone indicating that risks have been reduced, but a
"no significant risk" level cannot be maintained-can be achieved. The MCP also establishes
an "activity and use limitation" requiring deed restrictions or deed notices to inform future
property owners and users of certain limits on activities at a site, unkjss additional response
actions are conducted. t
?
New Jersey i
' '.'- ! - ."
New Jersey applies risk-based decision-making~based on assessments of current and
potential future risk~at sites where discharges of hazardous substance? have occurred. The
process allows UST owners and operators to move forward in an expibditious manner with
minimal State oversight. !
' - '!'"'
After the State receives the results of an initial site investigation or remedial
investigation, sites are ranked using the Remedial Priority Scoring (RPS) system. The RPS
takes into account actual and potential exposure through air, surface water, ground water,
and direct contact, as well as fire and explosion hazards, biothreat, and subsurface migration
of contaminants. It reflects consideration of receptor distances, population density,
contaminant levels, toxicity, waste quantity, soil type, and aquifer uszige. UST cases are
assigned priority rankings based on RPS scores. j
The State's technical regulations specify the minimum requirements for conducting
investigations and remedial actions; they also prescribe reporting fbrn|iats. UST owners and
operators are allowed to use field screening methods for soil and groundwater and to
undertake single-phased remedial actions (i.e., UST removals) at non[complex sites-instead
of sequentially performing a preliminary assessment, site investigation, remedial
investigation, and remedial action. By following the technical regulations, UST owners and
operators receive a level of assurance that the work conducted without State oversight will be
accepted. ' . !
Combining the technical regulations with the State's cleanup criteria and Groundwater
Quality Standards (GWQS) allows UST owners and operators to complete a consistent
baseline delineation of contamination to appropriate levels without haying to develop site-
specific cleanup numbers. Soil Cleanup Criteria have been developed for 107 compounds;
most have residential and non-residential direct contact and impact-topgroundwater numbers.
The soil cleanup criteria were derived from Superfund risk assessment guidance and other
State and EPA data. Soil with contamination below residential levels is considered
acceptable for unrestricted direct contact use.
j
Since most groundwater in New Jersey is classified as potable aquifers, groundwater
delineation to the GWQS is required. In areas not classified as "potable aquifers,"
delineation has to be conducted only to check for possible impairment of existing
groundwater uses, violations of surface water quality standards, retea'ses of pollutants to
ground surface or buildings, and contaminant migration to potable aquifers.
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OSWER Directive 9610.17
March 1, 1995.
Once soU and groundwater delineation are completed, a risk-based decision is made
on the need for active or passive remediation. This decision is based on the extent of
contamination, proximity of receptors, and nature of exposure pathways. Li many instances
natural remediation of petroleum-contaminated groundwater is acceptable following source '
removal (including any free product), where no receptors are at risk and conditions are
conducive to natural attenuation. Where soil contamination exceeds residential and non-
residential direct contact cleanup criteria, contaminants may remain if appropriate
institutional and engineering controls are applied to prevent current and future direct contact
The levels of contaminants that can remain are determined on a site-by-site basis.
UST owners and operators have the option of conducting a risk assessment in
accordance with EPA guidance. UST owners and operators conducting cleanups with their
own funds have the option of completing cleanups to unrestricted levels to avoid the use of
institutional controls.
Reference Documents
Risk-Based Corrective Action for Leaking Storage Tank Sites. RG-36, Texas Natural
Resource Conservation Commission, January 1994.
Risk Assessment Guidance Document For Risk Assessors and Project Managers-DRAFT
Ohio Department of Commerce, Division of State Fire Marshal, Bureau of Underground °
Storage Tank Regulations, July 28, 1994.
Technical Guidance Manual for Underground Storage Tank Closure and Release Response
State of Hawaii Department of Health, Environmental Management Division, August 1992.
The 1993 Massachusetts Contingency Plan - A New Cleanup Approach To Cleaning Up
Disposal Sites. Department of Environmental Protection, August 12,-1993.
The Illinois Leaking Underground Storage Tank Program: A Summary of Recent
Developments, Illinois Environmental Protection Agency, October 1994. -
New Jersey Technical Requirements for Site Remediation. NJAC 7:26E (Technical
Regulations).
New Jersey SoU Cleanup Criteria. In the April 1994 Site Remediation News.
Oversight of the Remediation of Contaminated Sites in New Jersey. NJAC 7:26C.
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